HomeMy WebLinkAbout2018-08-06 MSCWMO Review Letter MIDDLE ST. CROIX WATERSHED MANAGEMENT ORGANIZATION
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4 5 5 HAYWARD AVE . N P.
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August 6,2018 MSW
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Eric Johnson,Administrator
City of Oak Park Heights
PO Box 2007
Oak Park Heights,MN 55082
RE: Palmer Station,Oak Park Heights
Dear Mr. Johnson,
The Middle St. Croix Watershed Management Organization (MSCWMO) received submittals on April 6th, 2018 and
revised submittals on July 2,2018 for the proposed Palmer Station subdivision,located within MSCWMO boundaries and
in the City of Oak Park Heights. The proposed project qualifies for full review under the MSCWMO 2015 MSCWMO
Watershed Management Plan(WMP).
The MSCWMO Board reviewed the revised plans dated July 2, 2018 and recommends approval with the following 5
conditions:
1) Submit dedication or easement of the property which are adjacent to the facility and which lie below the 100 year
flood level.
2) Submit a maintenance agreement in a format approved by the City.
3) Identify inlet protection for stormwater inlets.
4) MIDS Calculator-North bioretention basin w/underdrain: Change BMP Parameter setting"Is a soil amendment
used to attenuate phosphorus"to No.
5) North Filtration Basin-reduce the length of the southern two runs of underdrain by 30.0' to reduce the potential of
stormwater short circuiting the filtration media.
The enclosed checklist contains detailed information on project review and the policies and performance standards of the
WMP. Feel free to contact me at 651-330-8220 x22 or misensee@mnwcd.org if you have any questions regarding these
comments.
Sincerely,
1/641.(74tetZte....L...
Mike Isensee
MSCWMO Administrator
Enclosure
Middle St. Croix Watershed Management Organization Member Communities
Afton, Bayport, Baytown, Lakeland, Lakeland Shores, Lake St. Croix Beach, Oak Park Heights, St. Mary's Point, Stillwater, &West Lakeland
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MIDDLE ST. CROIX WATERSHED MANAGEMENT ORGANIZATION
4 5 5 HAYWARD AVE . N .
O A K D A L E , MINNESTOA 5 5 1 2 8 \�
Phone 651 . 330 . 8220 x22 fax 651 . 330 . 7747 www . mscwmo . org
PROJECT REVIEW MSCWM'p
MSCWMO Project Review ID: 17-12
Project Name: Orchards at Cahanes Farm
Purpose: Residential Development
Location: Baytown Township
Review date: 6/22/2018
Recommendation: Approve with 16 conditions:
1. Consider adding construction phasing and required site plan areas for temporary erosion and sediment
control. The site contains a lot of topography and wetlands that will require planning and attention to
detail to prevent violations to the NPDES permit and the wetland conservation act.
2. Dewatering of highly turbid ponds will be a necessity to avoid wetland impacts during construction. Provide a
detailed description of the recommended dewatering techniques.
3. The plans contain a detail for V notch ditches. These ditches are prone to erosion. Please indicate where these
ditches are proposed and demonstrate proposed permanent stabilization is sufficient to withstand design flows.
4. Add the following pollution prevention management guidance measures: vehicle and equipment
washing, no engine degreasing allowed on site, containments of concrete and other washout waste,
portable toilets are positioned so that they are secure.
5. Identify erosion control timeframes of 14 days (or 7 days for Appendix A waters within one mile of the
project area),wetted perimeters of ditches stabilized within 200 feet of surface water within 24 hours, pipe
outlets have energy dissipation within 24 hours of connecting.
6. Provide written documentation from the Township Engineer that low floor elevations variances are
acceptable.
7. Remove topsoil from infiltration and bioretention basins. Consider tilling 3" of MnDOT type 2 leaf liter
compost 6" deep in the native soils.
8. Remove the surface geotextile from under the filtration basin rock.
9. Remove the geotextile and pea rock around the under drain of the filtration basin. Replace with a
circular knit sock. Raise the underdrain 0.5' off the bottom of the native soils.
10. Identify temporary sediment basins at locations where 10 acres or more are draining to a common
location.
11. Add pretreatment to the stormwater pipe discharging to infiltration basin 1.
12. At what intensity does the 1.1" storm event bypass the infiltration facility in each of proposed
structure scenarios?
13. Provide an erosion mat specification for the detail "Erosion Mat Weir Overflow Spillway Section For
Infiltration Basins.
14. Remove gate valves and flush valves and add temporary plugs to keep infiltration facilities off line
during construction.
15. Correct the following outstanding stormwater calculation issues:
Middle St. Croix Watershed Management Organization Member Communities
Afton, Bayport, Baytown, Lakeland, Lakeland Shores, Lake St. Croix Beach, Oak Park Heights, St. Mary's Point, Stillwater, 8 West Lakeland
July 19,2018
Page 2 of 11
a. a/b/c/ Post nothing routed to 24p, 4p doesn't have the eof listed.
b. Wp6 detail doesn't match hydrocad- area 100 yr not in pdf 930 vs 929.5 eof
c. Wp8 detail doesn't match hydrocad- area 100 yr not in pdf,
d. Wp7 detail doesn't match hydrocad- 907.75 vs 908 eof
e. Wp4 12" orifice invert does not match between details, one of the details doesn't match model,
also doesn't have the eof listed.
f. Wp1 detail doesn't match hydrocad: 21" plan orifice doesn't match 12" orifice in model. eof
878.5 vs 879
g. Wp5 detail doesn't match hydrocad- doesn't have the eof listed.
h. Wp3 detail doesn't match hydrocad- 886.75 vs 887
16. Add the following infiltration basin construction guidance:
a. Excavation within 2.0 feet of final grade for infiltration/filtration systems is prohibited until
contributing drainage areas are constructed and fully stabilized.
b. Rigorous sediment and erosion controls planned to divert runoff away from the system.
c. Installation of volume control facilities must occur in dry soil conditions. Excavation, soil
placement and rapid stabilization of perimeter slopes must be accomplished prior to the next
precipitation event.
d. Excavation shall be performed by an excavator with a toothed bucket. Use excavator bucket to
place materials. Construction equipment shall not be allowed into the basin.
e. Prior to the release of any remaining fee or security, the permit holder must provide
documentation that constructed volume control facilities perform as designed.
Applicability:
® Any project undertaking grading,filling, or other land alteration activities that involve movement of 100 cubic
yards of earth or removal of vegetation on greater than 10,000 square feet of land
® Any project that creates or fully reconstructs 6,000 square feet or more of impervious surface
® All major subdivisions or minor subdivisions that are part of a common plan of development. Major
subdivisions are defined as subdivisions with 4 or more lots.
❑ Any project with wetland impacts
❑ Any project with grading within public waters
❑ Any project with grading within buffers
❑ Any project with grading within 40-feet of the bluff line
❑ Development projects that impact 2 or more of the member communities
Middle St. Croix Watershed Management Organization
MEMBER COMMUNITIES:
Afton,Bayport,Baytown Township,Lakeland,Lakeland Shores,Lake St.Croix Beach,Oak Park Heights,St.Mary's Point,Stillwater and West Lakeland Township
July 19, 2018
Page 3 of 11
n New or redevelopment projects within the St. Croix Riverway that require a building permit that adds five
hundred (500) square feet or more of additional impervious surface
n Any project requiring a variance from the current local impervious surface zoning requirements for the
property
n Any land development activity, regardless of size,that the City determines is likely to cause an adverse impact
to an environmentally sensitive area or other property, or may violate any other erosion and sediment control
standard set by the member community.
SUBMITTAL ITEMS:
Electronic submittals are highly encouraged
® A completed and signed project review application form and review fee
® Grading Plan/Mapping Exhibits
a. Property lines and delineation of lands under ownership of the applicant.
b. Delineation of existing on-site wetlands, shoreland and/or floodplain areas (including any buffers).
c. Ordinary High Water(OHW) elevations and datum,as determined by the MDNR (if applicable).
d. Existing and proposed site contour elevations related to NAVD 1988 datum (preferred)or NGVD, 1929.
Datum must be noted on exhibits.
e. Drainage easements covering land adjacent to ponding areas,wetlands, and waterways up to their 100-year
flood levels and covering all ditches and storm sewers.Access easements to these drainage easements
and to other stormwater management facilities shall also be shown.
f. Minimum building elevation for each lot.
g. Identification of downstream water body.
® Permanent Stormwater Management System in compliance with the requirements of the NPDES SDS
Construction Stormwater Permit and MSCWMO Performance Standards.
a. Impervious areas (Pre-and Post-Construction).
b. Construction plans and specifications for all proposed stormwater management facilities.
c. Location(s) of past, current or future onsite well and septic systems (if applicable).
n Other exhibits required to show conformance to these Performance Standards
n A Stormwater Pollution Prevention Plan in compliance with the requirements of the NPDES SDS Construction
Stormwater Permit
® Grading Plan/Mapping Exhibits:
a. Delineation of the subwatersheds contributing runoff from off-site, proposed and existing on-site
subwatersheds, and flow directions/patterns.
Middle St. Croix Watershed Management Organization
MEMBER COMMUNITIES:
Afton,Bayport,Baytown Township,Lakeland,Lakeland Shores,Lake St.Croix Beach,Oak Park Heights,St.Mary's Point,Stillwater and West Lakeland Township
July 19,2018
Page 4 of 11
b. Location, alignment, and elevation of proposed and existing stormwater facilities.
c. Existing and proposed normal water elevations and the critical (the highest)water level produced from the
100-year 24-hour storms.
d. Location of the 100-year flood elevation, natural overflow elevation, and lowest floor elevations.
® Hydrologic/Hydraulic Design Exhibits:
a. All hydrologic and hydraulic computations completed to design the proposed stormwater management
facilities shall be submitted. Model summaries must be submitted.The summaries shall include a map that
corresponds to the drainage areas in the model and all other information used to develop the model.
b. A table (or tables) must be submitted showing the following:
i. A listing of all points where runoff leaves the site and the existing and proposed stormwater runoff rates
and volumes.
ii. A listing of the normal water levels under existing and proposed conditions and the water levels produced
from the storm and runoff events listed above for all on-site wetlands, ponds, depressions, lakes,streams,
and creeks.
NA Dedications or easements for the portions of the property which are adjacent to the facility and which lie below
the 100 year flood level. For sites within public right-of-way, no easement is required.
_ A proposed maintenance agreement,which may be in the format of Appendix K, or other form approved by the
city.
HISTORY& CONSIDERATIONS:
SPECIAL OR IMPAIRED WATER
NA This site drains to, and is within one mile of special or impaired water and complies with enhanced protections.
a. Scenic or Recreational river C.1., C.2., C.3.
b. Scientific and Natural area C.1., C.2., C.3.
c. Waterbody with a TMDL C.1., C.2.
C.1. Stabilization initiated immediately and all soils protected in seven days/provide temp basin for five acres
draining to common location.
C.2. Treat water quality volume of one inch of runoff by retaining on site unless not feasible due to site
conditions (See Part III.D.1. design requirements).
C.3. Maintain buffer zone of 100 linear feet from Special Water.
EROSION AND SEDIMENT CONTROL [A checked box indicates compliance]
n A Stormwater Pollution Prevention Plan (SWPPP)that meets the National Pollutant Discharge Elimination System
(NPDES)requirements.
Middle St. Croix Watershed Management Organization
MEMBER COMMUNITIES:
Afton,Bayport,Baytown Township,Lakeland,Lakeland Shores,Lake St.Croix Beach,Oak Park Heights,St.Mary's Point,Stillwater and West Lakeland Township
July 19,2018
Page 5 of 11
Narrative
® Identify the person knowledgeable and experienced who will oversee the implementation of the SWPPP;the
installation, inspection, and maintenance of the BMPs.
a. Identifies the person who will oversee the BMP inspection and maintenance.
b. Identify the training requirements are satisfied.
c. Inspections performed once every 7 days.
d. Inspections performed within 24 hours of a rain event greater than 0.5 in/24 hours.
e. Inspection and Maintenance records include:
i. Date and time of inspection.
ii. Name of person(s) conducting inspections.
iii. Finding of inspections, including the specific location where corrective actions are needed.
iv. Corrective actions taken (including dates,times, and party completing maintenance activities).
v. Date and amount of rainfall events greater than 0.5 in/24 hours.
vi. Rainfall amounts must be obtained by a properly maintained rain gauge installed onsite,or by a
weather station that is within one mile or by a weather reporting system.
vii. Requirements to observe, describe, and photograph any discharge that may be occurring during the
inspection.
viii. All discovered nonfunctional BMPs must be repaired, replaced, or supplemented with functional
BMPs within 24 hours after discovery, or as soon as field conditions allow.
® Describes procedures to amend the SWPPP and establish additional temporary ESC BMPs as necessary for site
conditions.
® Describes the installation timing for all Erosion Sediment Control (ESC) Best Management Practices (BMPs).
® Describes final stabilization methods for all exposed areas.
® Methods used to minimize soil compaction and preserve topsoil must be described.
III Describes dewatering technique to prevent nuisance conditions,erosion,or inundation of wetlands.
ri Identifies any specific chemicals and the chemical treatment systems that may be used for enhancing the
sedimentation process on the site, and how compliance will be achieved with the permit requirements.
El Describes pollution prevention management measures
a.Storage, handling,and disposal of construction products, materials, and wastes.
b. Fueling and maintenance of equipment or vehicles;spill prevention and response.
c.Vehicle and equipment washing.
d. No engine degreasing allowed on site.
e. Containment of Concrete and other washout waste.
Middle St. Croix Watershed Management Organization
MEMBER COMMUNITIES:
Afton,Bayport,Baytown Township,Lakeland,Lakeland Shores,Lake St.Croix Beach,Oak Park Heights,St.Mary's Point,Stillwater and West Lakeland Township
July 19,2018
Page 6 of 11
f. Portable toilets are positioned so that they are secure.
Plan sheets
D Temporary Sediment Basins required(10 acres draining to common location or 5 acres App. A)
Basin design meets the following criteria:
a. Adequately sized—2-year, 24-hour storm, minimum 1,800 feet/acre; or no calculative minimum
3,600ft3/acre.
b. Designed to prevent short circuiting.
c. Outlets designed to remove floating debris.
d. Outlets designed to allow complete drawdown.
e. Outlets designed to withdraw water from the surface
f. Outlets have energy dissipation.
g. Have a stabilized emergency spillway.
h. Situated outside of surface waters and any natural buffers.
® Locations and types of all temporary and permanent Erosion Control BMPs.
a. Exposed soils have erosion protection/cover initiated immediately and finished within 14 days (or 7 days
Appendix A).
b. Wetted perimeters of ditches stabilized within 200 feet of surface water within 24 hours.
c. Pipe outlets have energy dissipation within 24 hours of connecting.
® Locations and types of all temporary and permanent Sediment Control BMPs.
a. Sediment control practices established on down gradient perimeters and upgradient of any buffer zones.
b. All inlets are protected.
c. Stockpiles have sediment control and placed in areas away from surface waters or natural buffers.
d. Construction site entrances minimize street tracking?
e. Plans minimize soil compaction and, unless infeasible to preserve topsoil.
f. 50 foot natural buffers preserved or(if not feasible) provide redundant sediment controls when a surface
water is located within 50 feet of the project's earth disturbances and drains to the surface water.
® Tabulated quantities of all erosion prevention and sediment control BMPs.
® Stormwater flow directions and surface water divides for all pre-and post-construction drainage areas.
® Locations of areas not to be disturbed (buffer zones).
® Location of areas where construction will be phased to minimize duration of exposed soil areas.
Middle St. Croix Watershed Management Organization
MEMBER COMMUNITIES:
Afton,Bayport,Baytown Township,Lakeland,Lakeland Shores,Lake St.Croix Beach,Oak Park Heights,St.Mary's Point,Stillwater and West Lakeland Township
July 19,2018
Page 7 of 11
NA Blufflines are protected from construction activities in urban (40 foot buffer)areas and rural areas(100 foot buffer).
LAKE, STREAM AND WETLAND BUFFERS
® A buffer zone of unmowed natural vegetation is maintained or created upslope of all water bodies (wetlands,
streams, lakes).
® A 50 foot natural buffer or(if a buffer is infeasible) provide redundant sediment controls when a surface water is
located within 50 feet of the project's earth disturbances and stormwater flows to the surface water.
NA If adjacent to a Special or Impaired Water an undisturbed buffer zone of not less than 100 linear feet from
the special water is maintained both during construction and as a permanent feature post construction.
STORMWATER MANAGEMENT[A checked box indicates compliance]
® Water quality treatment is provided prior to direct discharge of stormwater to wetlands and all other water bodies.
Rate and Flood Control Standards
® The peak rate of stormwater runoff from a newly developed or redeveloped site shall not exceed the 2-, 10-, and
100-year 24-hour storms with respective 2.8,4.2, and 7.3-inch rainfall depths with MSCWMO approved time
distribution based on Atlas 14 for existing and proposed conditions. The runoff curve number for existing
agriculture areas shall be less than or equal to the developed condition curve number.The newly developed or
redeveloped peak rate shall not exceed the existing peak rate of runoff for all critical duration events, up to and
including the 100-year return frequency storm event for all points where discharges leave a site during all phases of
development.
® Predevelopment conditions assume"good hydrologic conditions"for appropriate land covers as identified in TR-55
or an equivalent methodology. Runoff curve numbers have been increased where predevelopment land cover is
cropland:
Hydrologic Soil Group A: Runoff Curve Number 56
Hydrologic Soil Group B: Runoff Curve Number 70
Hydrologic Soil Group C: Runoff Curve Number 79
Hydrologic Soil Group D: Runoff Curve Number 83
Computer modeling analyses includes secondary overflows for events exceeding the storm sewer systems level-of-
service up through the critical 100-year event.
• In sub-areas of a landlocked watershed,the proposed project does not increase the predevelopment volume or
rate of discharge from the sub-area for the 10-year return period event.
Middle St. Croix Watershed Management Organization
MEMBER COMMUNITIES:
Afton,Bayport,Baytown Township,Lakeland,Lakeland Shores,Lake St.Croix Beach,Oak Park Heights,St.Mary's Point,Stillwater and West Lakeland Township
July 19,2018
Page 8 of 11
• Flowage easements up to the 100-yr flood level have been secured for stormwater management facilities (such as
ditches and storm sewers).
❑ Lowest floor elevations of structures built adjacent to stormwater management features and other water bodies
are a minimum of two feet above the 100-year flood elevation and a minimum of two feet above the natural
overflow of landlocked basins. Variance requested
Volume Control Standards
® Calculations/computer model results indicate stormwater volume is controlled for new development and
redevelopment requirements per the MSCWMO Design Standards.
1. New Nonlinear Development 1.1" * new impervious surfaces
2. Reconstruction/Redevelopment Projects 1.1" * reconstructed impervious surfaces
3. Linear Projects 0.55" * new and/or fully reconstructed impervious surface and 1.1"from net increase in
impervious area
4. Sites with Restrictions-flexible treatment options documentation has been provided.
Volume Retention Required (cu.ft.) Volume Retention Provided (cu.ft.)
BMP Volume
967,600 sf*1.1" = 88,697 cu.ft. BMP#1 29,152 cu.ft.
BMP#2 27,384 cu.ft.
BMP#3 7,262 cu.ft.
Total Required 88,697 cu.ft. BMP#4 23,711 cu. ft.
BMP#5 filter
BMP#6 12,055 cu.ft.
BMP#7 filter
BMP#8 O cu.ft.
BMP#9 6,941 cu.ft.
BMP#10 26,608 cu. ft.
Total Proposed 133,113 cu.ft.
Flexible Treatment Options(when applicable)
NA Applicant demonstrated qualifying restrictions as defined in Section 7.2.2 (4) of the 2015 MSCWMO Watershed
Management Plan that prohibits the infiltration of the entire required volume.
NA MIDS calculator submission removes 60%of the annual total phosphorous.
Infiltration/Filtration Design Standards
❑ Proposed stormwater management features meet or exceed NPDES General Construction Permit requirements are
designed in conformance with the most recent edition of the State of Minnesota Stormwater Manual.
Middle St. Croix Watershed Management Organization
MEMBER COMMUNITIES:
Afton,Bayport,Baytown Township,Lakeland,Lakeland Shores,Lake St.Croix Beach,Oak Park Heights,St.Mary's Point,Stillwater and West Lakeland Township
July 19,2018
Page 9 of 11
a. Topsoil is prohibited in infiltration and bioretention systems.
None of the following conditions exist that prohibit infiltration of stormwater on the site
a. Areas where vehicle fueling and maintenance occur.
b. Areas with less than three (3)feet of separation distance from the bottom of the infiltration system to the
elevation of the seasonally saturated soils or the top of bedrock.
c. Areas where industrial facilities are not authorized to infiltrate industrial stormwater under an National
Pollutant Discharge Elimination System (NPDES)/State Disposal System (SDS) Industrial Stormwater Permit
issued by the MPCA.
d. Areas where contaminants in soil or groundwater will be mobilized by infiltrating stormwater.
e. Areas of Hydrologic Soil Group D (clay) soils
f. Areas within 1,000 feet up-gradient, or 100 feet down-gradient of active karst features unless allowed by a
local unit of government with a current MS4 permit.
® Minimum setbacks from the Minnesota Department of Health for infiltration practices are met
Setback Minimum Distance(ft)
Property line 10
Building foundation* 10
Private well 35
Public water supply well 50
Septic system tank/leach field 35
*Minimum with slopes directed away from the building
El Pretreatment devices(s) remove at least 50%of sediment loads. If downstream from a potential hot spot, a
skimmer is in place to facilitate cleanup. Inf. 1 pipe discharge requires pretreatment
0 Water quality volume will be discharged through infiltration or filtration media in 48 hours or less. 7f 8, inf 10
a. For bioretention (biofiltration and bioinfiltration)volume control management facilities above ground with
vegetation the period of inundation shall be calculated using the maximum water depth below the surface
discharge elevation and the soil infiltration rate.
b. For infiltration basin volume control management facilities the period of inundation shall be calculated using the
maximum water depth below the surface discharge elevation and the soil infiltration rate.
Appropriate soil borings have been conducted that meet the minimum standards.
a. A minimum of one boring was conducted at the location of the infiltration facility for facilities up to 1,000 ft2;
between 1,000 and 5,000 ft2,two borings, between 5,000 and 10,000 ft2,three borings and greater than 10,000
ft2 4 borings plus an additional boring for every 2,500 ft2 beyond 12,500 ft2
Middle St. Croix Watershed Management Organization
MEMBER COMMUNITIES:
Afton,Bayport,Baytown Township,Lakeland,Lakeland Shores,Lake St.Croix Beach,Oak Park Heights,St.Mary's Point,Stillwater and West Lakeland Township
July 19,2018
Page 10 of 11
b. Soil borings extend a minimum of five feet below the bottom of the infiltration practice. If fractured bedrock is
suspected,the soil boring goes to a depth of at least ten feet below the proposed bottom of the volume control
facility.
c. A minimum of three feet of separation to the seasonal water table and/or bedrock.
d. Identify unified soil classification.
▪The least permeable soils horizon identified in the soil boring dictated the infiltration rate. Inf 8, inf 10
n Additional flows are bypassed and are routed through stabilized discharge points.
® Filtration practices demonstrates a basin draw down between 24 hours and 48 hours.
® Filtration system designed to remove at least 80%of total suspended solids
NA Filtration system Iron Enhanced Sand Filter is sized to bind soluble phosphorous removal for 30 year functional life of
the system using the published value of 17lbs.phosphorous removal per 20 yards of 5% by weight iron filings to 95%
sand.
0 Construction plans provide adequate construction guidance to prevent clogging or compaction and demonstrate
performance.
a. Excavation within 2.0 feet of final grade for infiltration/filtration systems is prohibited until contributing
drainage areas are constructed and fully stabilized.
b. Rigorous sediment and erosion controls planned to divert runoff away from the system.
c. Installation of volume control facilities must occur in dry soil conditions. Excavation,soil placement and rapid
stabilization of perimeter slopes must be accomplished prior to the next precipitation event.
d. Excavation shall be performed by an excavator with a toothed bucket. Use excavator bucket to place materials.
Construction equipment shall not be allowed into the basin.
e. Prior to the release of any remaining fee or security,the permit holder must provide documentation that
constructed volume control facilities perform as designed.
® There is a way to visually verify the system is operating as designed.
®A minimum 8.0' maintenance access is provided to all stormwater facilities.
Hydrocad time span could be longer(5 20 hrs), did we set time span in the plan update????
a/b/c/ Post nothing routed to 24p, 4p doesn't have the eof listed.
Wp9 • -' - - - , _„ . - . - :" - . . - • - --
cof listed.
Middle St. Croix Watershed Management Organization
MEMBER COMMUNITIES:
Afton,Bayport,Baytown Township,Lakeland,Lakeland Shores,Lake St.Croix Beach,Oak Park Heights,St.Mary's Point,Stillwater and West Lakeland Township
July 19, 2018
Page 11 of 11
Wp6 detail doesn't match hydrocad: 6" orifice on plan is missing in nmol,18" orifice is 60" on plan g area
yr not in pdt 930 vs 929.5 eof
Wp8 detail doesn't match hydrocad: ;" _ ' ' - _ _ - • -- -_ - - _ _ . :" - • • - • ,e" _ g area
yr not In pa,,
Wp7 detail doesn't match hydrocad: _ _ _ __ -' . - e •- - _ _ _ • • - -
12" dia orifice in 2 details and neither arc in model. 907.75 vs 908 eof
Wp4 detail doesn't match hydrocad: 24x24 on plan doesn't match 24x30 in model, 8" orifice doesn't match
12" orifice in 2 details and neither arc in model. 12" orifice invert does not match between details, one or the
details doesn't match model. _ - _ -- _ _ . -• e - - -
match inverts. Model 12' culvert is 100', plan shows 14'. Detail structure diameters don't match each other.
doesn't have the eof listed.
Wp1 detail doesn't match hydrocad: .1" plan orifice doesn't match 12" orifice in model; 12" culvert, 48" or
. . -
cof listed eof 878.5 vs 879
Wp5 detail doesn't match hydrocad: 30" pipe lengths don't , Details contradict size of
structure 18" or 60„ ° itw a 1, doesn't have the eof listed.
Wp3 detail doesn't match hydrocad: " - • . - _ _ - - - _„ _ ' • - - - _ _ _• -:• -
- - ' • - --: : - • -: ' :", 12" pipe length doesn't match,doesn't have the eof listed. 886.75
vs 887
Middle St. Croix Watershed Management Organization
MEMBER COMMUNITIES:
Afton,Bayport,Baytown Township,Lakeland,Lakeland Shores,Lake St.Croix Beach,Oak Park Heights,St.Mary's Point,Stillwater and West Lakeland Township